A great blow, or staff. I’ll tip him a jordain if I transnear; i.e. I’ll give him a blow with my staff, if I come near him. Cant.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
See also the definition in Nathan Bailey's 1721 dictionary of canting and thieving slang.
Jolter Head * JordanNathan Bailey's 1721 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes